Conventionally, various advertising media that appeal to people's vision are used for publicity of companies or products. For example, billboards and signboards located in public places or the like, or television commercials have been widely adopted.
Since an object of advertisement is to be seen by people, leading to recognition of information of companies and products, various ideas have been suggested for attracting people's attention.
For example, as for signboards, a method for blinking a display or moving displayed information is employed. As for television commercials, various images can be provided compared with the signboards or the like. Therefore, viewers' attention is attracted by ideas such as giving not only images but also a story to contents.
Recently, various images can be provided other than televisions along with the spread of digital displays. Therefore, digital signage (electronic advertising system) spreads which displays images and information using a flat panel display, a projector or the like even in the outdoors. Then, various methods have been developed even in the field of digital signage in order to attract people's attention (Patent Literature 1, 2 and the like).
Patent Literature 1 discloses a technique for displaying advertisement details corresponding to an advertisement outline that is downloaded to a portable terminal of a person who is around a display screen.
Patent Literature 2 discloses a technique for changing display contents by receiving a signal from a portable terminal of a person who is viewing a display screen.
That is, the techniques in Patent Literatures 1 and 2 are for attracting person's attention to the display screen by changing the displayed contents on the display screen of the digital signage according to the person who is the most likely to view the screen.
On the other hand, as for digital signage with a large display provided on a wall surface of a building or the like, the same screen is simultaneously viewed by the general public, leading to difficulty in employing the techniques in Patent Literatures 1 and 2.
With digital signage using a small display provided in stores or on vending machines, eagerness to buy can be increased by employing the techniques in Patent Literatures 1 and 2. However, in the case of displaying an advertisement aim at specific people in such a situation that a plurality of people views the same display, interest of the others may be impaired. Situations in which the techniques in Patent Literatures 1 and 2 can be employed are therefore limited.
A technique for providing special information only to specific people has also been developed even in the case where the plurality of people views the same display (Patent Literature 3 to 6, or the like).
Patent Literatures 3 and 4 disclose techniques in which, as an image displayed on a display that shows information from a computer, a screen having information for providing to specific people displayed thereon (display target screen) and a screen in complementary color relationship with the display target screen (screen in complementary color) are prepared to be alternately displayed on the display, and therefore, people cannot recognize the display target screen when normally viewing the display (see FIG. 16). Patent Literatures 3 and 4 also disclose methods, as a method for reading information on the display target screen, in which special glasses are used and only a person who wears the glasses can read the information on the display target screen.
Patent Literatures 5 and 6 disclose techniques in which a concealment design including concealed information is displayed, and then the concealed information can be visually recognized by viewing the concealment design through a special card or the like (see FIG. 17).
By employing the above processing to images displayed on the large display according to such techniques, special information can be provided to people having the special glasses or the special card. That is, even in the case where the plurality of people views the same display, information that attracts specific people can be provided to the people.